Synthesis and properties of multipod-shaped ZnO nanorods for gas-sensor applications

We reported the synthesis and optical properties of ZnO nanorods with multipod shapes, and their applications as gas sensors. The multipod-shaped ZnO (M-ZnO ) nanorods, having tens of needle-like nanorods united at a common junction, exhibited different structural and optical characters from those of the tetrapod-shaped ZnO (T-ZnO) nanorods. Employing the M-ZnO and the T-ZnO nanorods, respectively, gas sensors were prepared and tested for the detection of ethanol in air. It was found that the M-ZnO devices had an improved sensing performance in comparison with that of the T-ZnO sensors, of which a possible sensing mechanism related to a surface reaction process was discussed.